The traditional bogie generally uses H-shaped frame and rigid cross beams, relying on the primary vertical flexible suspension to overcome the distortion and irregularity of a rail. When wheelsets pass the transition curve, part of the rigid frame bears greater torque effect due to the high curved track. Moreover, when speed is fast, the connecting part between the frame and the primary vertical flexible suspension also bears a greater force. In the traditional structural design of a bogie, the motor is mounted on the frame. In order to allow the dynamic disturbance between the motor and wheelsets as well as to transmit torque, complex mechanisms such as coupling and gear box need to be arranged. This kind of bogie has complex structure, low productivity, larger distance of shaft, and greater weight, therefore performance indicators such as small radius curved-track negotiation, energy saving and submissiveness to the line irregularity cannot be improved significantly.
The search found a Chinese invention patent CN101565049 B, which discloses a bogie of hinged frame linear electric motor. Two T-shaped frames are respectively hinged on the central cross beam through rubber nodes. The side part of the central cross beam is connected to the upper traction cross beam through a longitudinal rod. The traction cross beam is connected to the first side cross beam and the second side cross beam through a hydraulic damper. The central cross beam is connected to the linear motor through the traction rod. This design can improve the bogie, transmit traction force, and improve the traction effect of the linear motor.
When wheelsets pass the transition curve, the two hinge points can be moderately distorted under a bigger torque to protect the frame. According to the files, the bogie realizes flexibility through the rubber nodes of hinges. According to the model of vehicle, different rubber nodes need to be designed for the bogie. The structure realizes torsion through rubber nodes. The performance parameters of rubber nodes have great discreteness. As the environment temperature changes, the performance parameters of rubber nodes are often quite different from the design value. At the same time rubber is liable to aging and cracking with poor reliability and relatively short service life. And the motor is still arranged on the bogie, the distance of shaft on the shaft is larger, therefore the various performance indexes of the bogie are not improved significantly.
The mark numbers in the diagram mean: 1—left side-frame, 2—wheel, 3—flexible drive devices, 4—permanent magnetic motor, 4′—permanent magnetic motor, 5—traction rod, 5′—traction rod, 6—longitudinal linking rod, 7—bridge plate, 8—right side-frame, 9—air spring, 10—rubber pad, 11—axle box, 12—anti-roll bar, 13—flexible cross beam, 14—flange disc, 15—rubber joint, 16—connection, 17—axle bushing, 18—traction rod bracket, 19—traction body, 20—secondary lateral damper, 21—secondary vertical damper, 22—lateral stop bracket, 23—flexible stop buffer, 24—first mounting bracket, 25—second mounting bracket, 26—swing arm bracket, 27—anti-roll bar bracket, 28—secondary lateral damper bracket, 29—flexible stop buffer bracket.